Apparatuses for assisted breathing are already known that comprise means for conveying a breathing gas into the lungs of a patient and, optionally, for removing said gas, via a breathing-assistance tube or probe whose distal end is generally designed to be inserted into the trachea of the patient. Under such circumstances, it is common practice to provide an inflatable balloon at the distal end of the tube for the purpose of sealing the tube to the trachea. The balloon is inserted into the trachea while in the deflated state, and it is then inflated once it has been installed therein. To inflate the balloon, an inflation gas generator is provided at the proximal end of the tube and is generally incorporated in the breathing gas generator. The inflation pressure of the balloon is determined independently of the pressure of breathing gas insufflated into the lungs of the patient, and in such a manner that the balloon bears continuously against the walls of the trachea and gives rise to sufficient sealing between the breathing-assistance tube and the trachea.
In spite of all the precautions that can be taken, such as limiting inflation pressure to the smallest value compatible with essential sealing, the thrust pressure exerted by the balloon against the walls of the trachea is traumatic therefor. This can give rise to severe consequences for the patient, such as necrosis of the tissue of the walls of the trachea.